Gas furnace



April 1, 1930 c. E. sczHum-z-r 1,752,460

GAS VFURNACE Filed July l5, 1927 Patented Apr. 1, 1930 PATENT OFFICECHARLES E. SCHULTZ, 0F CHICAGO, ILLINOIS GAS FURNACE Application mea,July 15,

The invention relates to a gas furnace and more particularly to afurnace adapted for useby confectioners.

The principal object of the invention is to 5 provide in a furnace ofthe character set lsurfant forth an improved burner construction whereina highly efficient intermixture of fuel gas with pref-heated air Vunderpressure is obtained with consequent increased efficiency of combustion.

Another object is to provide improved means for heating-the air beforeit is mixed with the fuel gas.

A further object is to provide an improved `arrangement of fuel jets andmixing chambers.

Other objects and advantages will be apparent in the following detaileddescription of a preferred embodiment of the invention which I haveselected for illustration in the accompanying drawings. It will beunderstood however, that various changes inlform, construction andarrangement may be made by those skilled in the art withoutdepartingfrom the spirit and scope of the invention as expressed in the appendedclaims.

l'Referring to the drawings, Figure 1 is a sectional elevation takenthrough the center of the apparatus.

Fig. 2 is la plan view with portions of the upper plates broken away. Y

Fig. 3 is a fractionalelevation showingt-he supportvof the burnerstructure. n

Fig.4 4 isa fractional elevation illustrating the air'conduit throughthe burner and its su ply-connection. v

- n the drawings the reference numerals 1 and 2 indicate "respectivelythe outer and inner walls of an insulating drum. The walls arepreferably of cylindrical form separated a substantial distance toenclose `'an insulting air space. The walls 1 and 2 are supported attheir lowenmargin upon an annular'base plate 3havingsuit'ableformation-to, receive and secure the walls 1 and l2. VThebase plateB is supported in any suitable mannen/it beingrshown herein tohave three 'ingilegsffll The` upper margins of thelwallsleandfu supportaf top plate 5 eftuetingauclosure yoigthe space `laetsweenfthe 1927.Serial N'o. 205,910.

walls and serving as a rest for utensils being heated.

Positioned within-the drum vis a burner structure which is supportedfrom the base plate Shy means of brackets 6 suitably secured to the baseplate and extending radially inward of the latter as illustrated in Fig.3. The inner ends of the brackets 6 carry a spacer sleeve 7 upon whichrests a burner casing secured thereto by means of a bolt 8 extendingthrough the bracket and the spacer sleeve and threaded into the burnercasing.

The `burner casing comprises a hollow annular outer portion, indicatedat 9, enclosing an annular duct 10, and from which extends inwardly aflange or web 11. The inner margin of the flange 11 supports astub-casing 12 depending from the flange and having a centrally disposedchamber 13.

A jet cap 14 is positioned above the subcasing 12 and supported upon theupper side of the flange 11,-the jet cap forming an end closure of theenlarged-upper portion of the chamber within the sub-casing 12. The jetcap 14 is provided with an annular series of jet openings 15 in thepreferably cylindrical lateral periphery of the cap, the openings beingformed with their axes at an angle to the radial direction from thecenter of the cap.

Supported uponrthe upper side of the annular portion 9 of the casing isa plate 16 spaced from the lower flange 11 and from the upper side ofthe jet cap 14 to form a chamber 17 enclosing the latter. The plate 16is provided with a plurality of suitable openings 18 communicating withthe chamber 17 between the .plate and flange.-

The lower portion ofthe sub-casing 12 supports a gas inlet fixture 19preferably screw threaded in to the bottom wall of thesubcasing andextending into the chamber 13. The inlet fixture 19 is provided with anorifice at its upper end opening into the chamber 13 and controlled by aneedle valve 20, adj ustably lsecured. in the lower wall of the fixtureVin conventional manner, and provided with anadjusting nut 21 outwardlyof the fixture. A pipe 22 leading from a supply of fuel gas (not shown)Vis connected-t0 the valve fixture 19 and is adapted to supply gas tothe valve orifice.

A plurality of air inlet connections, in the present instance comprisingfour radially arranged pipes 23, enter the side walls of the sub-casing12 so as to communicate with the preliminary mixing chamber 13. Thepipes 23 lead upwardly at their outer ends and enter the hollow annularcasing 9, the upper ends of the pipe preferably extending a sublstantialdistance into the annular chamber or air heating duct and being suitablysecured thereto as by being threaded into the lower wall of the casing.Air supply connections are provided in the pipe 2a leading from a sourceof supply of air (not shown), the supply preferably being under moderatecompression. The pipe 24e herein communicates with a pair of branches 25which extend upwardly and enter within the chambered portion 9 throughthe lower wall of the casing, being suitably secured thereto asindicated in Fig. 4. For convenience in igniting the gas mixturedischarged from the f apertures 18, a pilot light 26 may be provided,herein illustrated as supported in the drum structure, and havingconnection with.

a constant supply of gas (not shown).

In operation, compressed air is brought to p the burner through thebranch connections nary mixing chamber 13, Where the fuel gas isadmitted through the valve 19 from the gas supply line. The air and gasare partially intel-mixed in the chamber 13 and discharged underpressure through the angularly arranged jet openings 15 into the finalmixing chamber 17, from which the combustible mixture passes through theopenings in the plate 16 and is burned within the combustion chamberformed by the enclosing drum. The heat of combustion radiated to theportion 9 of the burner casing effects the heating of the air passingthrough the annular chamber therein to a high degree, and promotes thecombustible intermixture with the fuel gas entering the subcasingchamber 13. The discharge of the hot mixture through the slanted jetopenings 15 effects a swirling movement within the chamber 17, whereinis accomplished a very thorough intermixture of the heated air and fuelgas at a temperature best suited for complete combustion above the plate16, and the production of an intense and highly eflicient flame.

It has been found that this construction materially increases theheating efficiency of a confectioners furnace over the ordinaryconstruction of burner heretofore in use, and effects a considerablesaving of time in the cooking of confections.

I claim as my invention:

1. In apparatus of the class described, a burner casing enclosing anouter circuitous air chamber and an inner final mixing chamber, saidlatter chamber having discharge orifices opening therefrom, a sub-casingmounted on said burner casing and enclosing a preliminary mixingchamber, a conduit connecting said air chamber and said preliminarymixing chamber, a partition member between said preliminary mixingchamber and said final mixing chamber having spirally disposed jetorifices effecting communication between said latter chambers, means forsupplying fuel gas to said preliminary chamber, and means for supplyinga current of air to said air chamber.

2. In apparatus of the class described, a burner casing having an airduct in its peripheral portion and having an inwardly extending flangeformed thereon, a plate mounted on said casing in spaced relation tosaid flange and forming a chamber therebetween, said platehavingdischarge orifices, a sub-casing mounted on said flange having achamber opening toward said first mentioned chamber, a closure memberbetween said chambers having an annular cap portion, said cap portionhaving a series of jet passages angularly disposed to their respectiveradial planes, and a conduit connecting said air duct to said sub-casingchamber.

3. A gas furnace of the class described comprising, in combination, acombustion chamber, means including a pair of substantially flat platesvertically spaced apart to form a circular and relatively shallow mixingchamber, the upper one of said plates having a plurality of dischargeports communicating with said combustion chamber, the lower one of saidplates having a central opening therein, a discharge head fitting int-osaid opening and projecting into said mixing chamber, said head having aseries of spirally disposed jet orifices discharging laterally into saidmixing chamber, said head further providing below said lower plate apreliminary mixing chamber, an outer circuitous air chamber disposedwithin the combustion chamber adapted for connection on the one handwith a source of air under pressure and on the other hand with saidpreliminary mixing chamber, and means connected with a source of fuelgas under pressure for discharging the same into said preliminary mixingchamber.

4. A gas furnace of the class described comprising, in combination witha combustion chamber, a burner structure providing an annular andrelatively shallow mixing chamber arranged centrally within saidcombustion chamber and having discharge ports in its upper sidecommunicating with the combustion chamber, means providing an annularair chamber adapted for connection with a source of air, and a dischargehead havingV a preliminary mixing chamber formed therein below the firstmentioned mixing chamber and connected With said air chamber and alsowith a source of fuel gas, said discharge head having its upper endprojecting into said first mixing chamber With a series of spirallydisposed jet orifices discharging laterally from the head. lo 5. Anapparatus of the class described including a burner structure having acircular plate with the peripheral portion shaped to provide an annularair chamber at the upper side of the plate, a second plate coacting 15with said annular portion to form With the first plate a circular andrelatively7 shallow chamber, the second of said plates having aplurality of discharge ports therein, and the first plate having acentral opening therein, 2C, a discharge head fitting into said openingand projecting into said chamber, said head having a central portionforming a preliminary mixing chamber, and a duct connecting said annularair chamber With said preliminary mixing chamber, said discharge headhaving a series of jet orifices discharging into said circular chamber.

In testimony whereof, I have hereunto affixed my signature.

a CHARLES E. soHULTZ.

